Limiting valve device.



W. V. TURNER.

LIMITING VALVE DEVICE.

APPLICATION FILED SEPT.3,191&

1,099,582a Patented June 9,1914.

INVENTOH WITN E'ssEs COLUMBIA PLANOGRAFH co.,wAsmNG'roN, n c.

UNITED s'rn'rns ragrnnr onnrcn.

WALTER V. TURNER, OF EDGEWOOD, PENNSYLVANIA, ASSIGNGH TO THE 'l/VESTING-HOUSE AIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANLl-i, A CORPORATION OFPENNSYLVANIA.

LIMITING VALVE -DIE!"VICE.

Application filed September 3, 1913.

1/ b all whom it may cone-cm Be it known that I, lVAL'rnR V. TURNER, acitizen of the United States, residing at l ldgewood, in the county tAllegheny and State of Pennsylvania, have invented new and usefulImprovements in Limiting Valve Devlces, of winch the following is aspec1ficat1on.

This invention relates to fluid pressure brakes, and more particularlyto means for limiting to a predetermined degree, the reduction in trainpipe pressure which, may be made by manipulation of the brake valve.

In my prior Patent No. 1,039,222, granted September 24, 1912, a valvedevice for accomplishing the above purpose is disclosed and comprises apiston subject to the oppos ingpressures of the usual equalizingreservoir and a limiting reservoir, normally at atmospheric pressure.The piston operates a valve for controlling the exhaust of fluid fromthe equalizing reservoir and in service application position of thebrake valve, fluid under pressure is supplied to the limiting reservoir.The limiting valve device has no influence on the operation until theequalizing reservoir pressure has been reduced to the equalizing pointand the pressure in the limiting reservoir has been increased to a pointslightly exceeding the reduced equalizing reservoir pressure andsuflicient to move the limiting piston and valve so as to close theexhaust from the equalizing reservoir. If after the limiting valvedevice has moved to the closed position, the brake valve should beallowed to remain in service application position, the pressure in thelimiting reservoir will continue to increase up to the degree ofpressure carried in the system. Ordinarily this would do no harm as theexcessive pressure in the limiting reservoir would be released in therelease position of the brake valve, but it for any reason, a secondbrake application is desired and the brake valve handle should beoperated to effect a reduction in train pipe pressure, it will be seenthat the limiting valve parts cannot move to the normal open positionuntil this excessive pres sure in the limiting reservoir has beenreleased or until the equalizing reservoir pressure preponderates. Thiscauses delay in securing an application 01 the brakes which might beundesirable at times.

The principal object of my invention is Patented June 9, 1914.

Serial No. 337327.

to obviate the above diilliculty and for this purpose means are providedfor limiting the increase in limiting reservoir pressure to the degreerequired for operating the limiting valve device.

In the accon'ipanying; drawing; Figure 1 is a diagrammatic view 01" abrake valve device connected up to the various reservoirs and thetrainpipe and embodyingmy improvement; Fig. 2 a central sectional viewor the brake valve device with the improved limiting valve deviceapplied, showlng the parts in the positions assumed upon movement of thebrake valve handle to service application position; Fig. 3 a similarview, showing the parts in the positions as sumed after equalization;Fig. 4 a fragmentary sectional view of the brake valve in releaseposition; and Fig. 5 a similar view, with the rotary valve in emergencyapplicatlon position. I

The brake valve proper may comprise the usual casing 1 having a valvechamber 2 connected to passage 3 which communieates with the mainreservoir at through pipe 5 and feed valve 29 and contains rotary valve6 adapted to be operated by brake valve handle 7.

Equalizing discharge valve piston S operates discharge valve 9 to ventlluid from chamber 10, at one side of the piston, to exhaust port 11,said chamber being connected by passages 12 and 13 to train pipe 1 1.Equalizing reservoir 15 communicates with chamber 16 at the oppositeside of the equalizing piston 8 through pipe 17 and pas sage 18.

The limiting valve device may comprise a casing 19 secured to the brakevalve casing 1 and having a piston chamber 20 containing a piston 21 foroperating a slide valve 22 contained in valve chamber A passage 2-1.leads from the piston chamber 20 to the seat of slide valve 22 and alsocommunicates with a passage 25 leading to the seat of rotary valve 6 andopen to passage 26 connected with pipe 27 leading to the limitingreservoir 28.

in the release position of the brake valve, as shown in of the drawing,port 30 in the rotary valve 6 registers with passage 31 leading to theequalizing piston chamber 16, so that the equalizing reservoir ischarged to the normal pressure carried in the system and fluid atequalizing reservoir pressure is also supplied from passage 18 throughpassage S2 to valve chamber Equalizing reservoir pressure in valvechamber 23 shifts the limiting valve piston to the position shown inFig. 2, and as passage 2% leading to piston chamber is connected throughpassage 25 and cavity 33 in the rotary valve 6 With exhaust port 3%, thelimiting valve piston 21 is normally maintained. in this position.

If the brake valve handle '7 is moved to service application position,as shown in Fig. of the drawing, the equalizing reservoir chamber 16 isconnected to the exhaust port 34: through passage 31, cavity 35 in therotary valve 6, passage 36, cavity 37 in the limiting slide valve 22,and passage 38, so that. fluid is vented from the equalizing reser voirto cause the operation of the equalizing discharge valve in the usualmanner. Fluid is also vented directly from the train pipe throughpassage 13, cavity 89 in the rotary valve 6, passage 10, cavity ll inthe limiting valve 22, and passage 42 to the exhaust port 34.

In the normal position of the limiting valve device, as shown in Fig. 2,passage 2% is connected to the rotary valve chamber 2 through cavity4e51- in the limiting valve 22, passage 4.4, and port to in the rotaryvalve, so that fluid is supplied topiston chamber 20 of the limitingvalve piston 21. The communication through which fluid is supplied tosaid piston chamber is preferably oi such capacity that the pistonchamber and the limiting reservoir 28 are charged to the desired degreeof pressure at which the train pipe pressure is limited to reduce to, insubstantially the same time that required to reduce the equalizingreservoir pressure to the same limiting degree of pressure. For example,if the normal train pipe pressure seventy pounds and the pressure atwhich the train pipe is limited to reduce to is fifty pounds, then thecommunication through which the limiting reservoir is charged is made ofsuch size that the limiting reservoir volume is charged from zero tofifty pounds in the same time as is required to reduce the equalizingreservoir pressure from seventy to fifty pounds.

If the brake valve handle should be left in service applicationposition, the pressure in the equalizing reservoir Will continue toreduce until the pressure in piston chamber 20 has increased to a pointslightly exceeding the reduced equalizing reservoir pressure andsufficient to shift the limiting valve piston 21 to the closed position,as shown in Fig. 3. The movement of the limiting slide valve 22 to thisposition cuts off the escape of fluid from the equalizing reservoir anddirectly from the train pipe and also closes communication fronrthesupply port 45 to the passage and the piston chamber 20.

it Will. now be evident that as the charging port for the piston chamber20 is cut off at the same time that the venting of fluid from theequalizing reservoir is cut ofl, further increase in pressure in saidpiston chamber is prevented.

is the limiting reservoir pressure is thus but slightly in excess of theequalizing reservoir pressure, when the brake valve handle is moved torelease position, the limiting valve piston is promptly shifted tonormal position, even Where the brake valve handle is moved quickly fromservice lap position to release position and then back to lap positionin the operation of graduating the release of the brakes. Consequently,it it should be desired to immediately re-apply the brakes, the limitingvalve parts \vill move promptly to normal position, so that the desiredservice reduction can be obtained without delay.

In emergency application position of the brake valve, as shown in Fig. 5of the drawing, a cavity 4.6 in the rotary valve 6 con nects the passage25 with exhaust port 3%, so that the limiting valve piston chamber 20 ismaintained at atmospheric pressure and the limiting valve piston thusprevented from moving. The limiting valve device is thus cut out ofaction in an emergency application, so that the train pipe pressure maybe reduced to any extent desired.

Having now described my invention, What I claim as new and desire tosecure bv Letters Patent, is I 1. In a fluid pressure brake, thecombination with a train pipe and a valve device operated by an increasein fluid pressure for limiting the reduction in train pipe pressure to apredetermined degree, of means for limiting said increase in fluidpressure.

2. In a fluid pressure brake, the combination With a train pipe and avalve device operated by an increase in fluid pressure for limiting thereduction in train pipe pressure to a predetermined degree, of means forlimiting said increase in fluid pressure to a degree suflicient tooperate said valve device.

3. In a fluid pressure brake, the combination With a train pipe and avalve device operated upon an increase in fluid pressure for limitingthe reduction in train pipe pressure to a predetermined degree, of meanscontrolled by said valve device for preventing an increase in fluidpressure on said valve device above the degree required to operate thevalve device. 7

4-. In a fluid pressure brake, the combination with a train pipe, abrake valve for ett'ecting a reduction in train pipe pressure, and avalve device operated upon an increase in fluid pressure for limitingthe reduction in train pipe pressure to a predetermined gree, of meanscontrolled bysaid'valve de vice for cutting ottthe flovv of fluid tosaid valve device upon movement thereof to limit the reduction in trainpipe pressure.

5. In a fluid pressure brake, the combination with a train pipe, a brakevalve having an equalizing discharge valve device operated by areduction in pressure in the equalizing reservoir for eii'ecting areduction in train pipe pressure, and a valve device subject on one sideto equalizing reservoir pressure and operated by an increase in fluidpressure on the opposite side for closing communication through whichfluid is vented from the equalizing reservoir, of means adapted uponclosing said communication to prevent further increase in fluid pressureon said valve device.

6. In a fluid pressure brake, the combination with a train pipe, a brakevalve having an equalizing discharge valve device operated by areduction in pressure in the equalizing reservoir for efi'ecting areduction in train pipe pressure, and a valve device subject on one sideto equalizing reservoir pressure and operated by an increase in fluidpressure on the opposite side for closing communication through whichfluid is vented from the equalizing reservoir, of means controlled bysaid valve device for cutting oil the flow of fluid under pressure forincreasing the fluid pressure on said valve device upon movement of saidvalve device to close said communication.

7. In a fluid pressure brake, the combination With a train pipe, a brakevalve having an equalizing discharge valve device operated by areduction in pressure in the equalizing reservoir for effecting areduction in train pipe pressure, and a valve device subject on one sideto equalizing reservoir pressure and operated by an increase in fluidpressure on the opposite side for closing communication through whichfluid-is vented from the equalizing reservoir, of means con trolled bysaid valve device for normally establishing a communication throughwhich fluid is supplied to operate said valve device, said.communication being closed by the movement of said valve device to closethe communication for venting fluid from the equalizing reservoir.

8. In a fluid pressure brake, the combination with a train pipe and abrake valve device having a direct and a preliminary eX haust port forell'ecting a reduction in train pipe pressure, of a limiting valvedevice separat-ely controlling said direct and preliminary exhaust portsfor limiting the reduction in train pipe pressure to a predeter mineddegree.

In testimony whereof I have hereunto set my hand.

W'ALTER V. TURNER.

Witnesses A. M. CLEMENTS, B. A. OLIVER.

copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. 0.

